NSRS Modernization: Replacing NAD 83 with NATRF2022

After 40 years of service, NAD 83 — the horizontal datum every US federal map, every USGS quadrangle, and every State Plane Coordinate System is referenced to — is being retired. So is NAVD 88, the vertical datum that defines “height above sea level” on every US topographic map. In their place, the US National Geodetic Survey is rolling out the largest overhaul of the National Spatial Reference System (NSRS) since the 1980s. This article covers what's changing, why, when, and what to do about it.

The /learn/what-is-a-geodetic-datum pillar covers what datums are. /learn/datum-transformations covers the transformation mechanics relevant to migrating data. This article is the US-specific timeline and the practical implications.

What's being replaced

| Old reference frame | New reference frame | Type | Replaced by | | ---------------------- | ------------------------ | ----------- | ---------------------------------------- | | NAD 83 (most CONUS) | NATRF2022 | Horizontal | Fixed to the North American plate | | NAD 83 (Pacific terr.) | PATRF2022 | Horizontal | Fixed to the Pacific plate | | NAD 83 (Caribbean terr.) | CATRF2022 | Horizontal | Fixed to the Caribbean plate | | NAD 83 (Mariana terr.) | MATRF2022 | Horizontal | Fixed to the Mariana plate | | NAVD 88 | NAPGD2022 | Vertical | Time-evolving geopotential model | | GEOID18 (conversion) | GEOID2022 | Geoid model | Integrated within NAPGD2022 |

The horizontal frames are plate-fixed: each is attached to a specific tectonic plate and moves with it. The collective name for the four new horizontal frames is the National Terrestrial Reference Frame (NTRF) 2022 series. The vertical reference is time-evolving: NAPGD2022 includes contemporary geopotential modelling so heights can be reported at specific epochs.

Why replace them

Three reasons:

1. NAD 83 has drifted from Earth's mass-centred frame

NAD 83 was defined in 1986 to align with the contemporary BIH (Bureau International de l'Heure) terrestrial reference. By the 2020s, accumulated drift between NAD 83 (a fixed historical frame) and the modern ITRF / WGS 84 (Earth-mass-centred, continuously updated) is about 1.5–2 m in CONUS. For sub-metre work — surveying, infrastructure as-builts, precision agriculture, autonomous-vehicle high-definition maps — this drift is a real and growing problem. NATRF2022 is aligned with the contemporary ITRF, with offsets at the centimetre level.

2. NAVD 88 has systematic tilts

NAVD 88 was the most carefully-levelled US vertical network of its era, but spirit-levelling over continental distances accumulates small systematic errors. Comparison of NAVD 88 against modern satellite gravimetry has revealed slow tilts on the order of 1–2 m across CONUS — small but problematic for hydrology, coastal flood-zone mapping, and infrastructure that crosses long distances. NAPGD2022 uses GRACE / GRACE-FO satellite gravity plus modern terrestrial measurements; the projected accuracy is sub-decimetre nationally, an order of magnitude better than NAVD 88.

3. Plate-fixed frames are needed for territorial accuracy

NAD 83 originally treated the entire US (including Hawaii, Puerto Rico, Guam) as if it were on a single plate. In practice the four plates the US territories sit on move independently — the Pacific plate, the Caribbean plate, and the Mariana plate all drift relative to North America at centimetres per year. A single plate-fixed frame for all of them accumulates noticeable error in the territories. The four-frame structure (NATRF2022, PATRF2022, CATRF2022, MATRF2022) gives each territory a frame that's stable relative to its own plate.

Timeline

A roughly-projected rollout, based on NGS's published schedule:

• 2022–2023: NGS finalises the technical specifications for the four new frames and NAPGD2022.
• 2024: NGS publishes Federal Register Notices announcing the new frames. Software vendors begin pre-release implementation.
• 2025: Federal mapping agencies (USGS, NOAA, FEMA) begin publishing new products in the new frames; legacy NAD 83 / NAVD 88 products remain available.
• 2026: NCAT supports bidirectional transformations between the legacy frames and the new ones. The new frames become the “current” reference for US federal work.
• 2027 and beyond: Gradual migration of state surveying conventions, infrastructure data, and software defaults. NAD 83 remains in use for legacy data; new data ships in the modern frames.

The transition isn't a hard cutover. NAD 83 and NAVD 88 remain valid references for years to come; the question is which frame new products are authored in. Federal mapping is moving; state and private data move on their own timelines.

What the new frames are aligned with

Unlike NAD 83 — which was effectively a stand-alone US reference frame — NATRF2022 (and its three sister frames) are explicitly aligned with the contemporary ITRF at the centimetre level. The alignment means:

• A coordinate in NATRF2022 differs from the same point's WGS 84 coordinate by only a few centimetres.
• Transformations between NATRF2022 and any other plate-fixed modern frame (ETRS89, GDA2020) become trivially close to identity transformations, with most of the offset coming from the plate-motion difference.
• The frames are explicitly tied to specific ITRF realizations, with documented transformation parameters for moving between ITRF epochs.

This is a fundamental architectural improvement over NAD 83, which required complex multi-stage transformations to integrate with global data.

Practical implications

For surveyors, infrastructure managers, and software developers, the migration has several practical effects:

1. Existing NAD 83 / NAVD 88 data doesn't become invalid. It remains a valid coordinate set; NCAT will support bidirectional transformations indefinitely.
2. New federal data will be in the new frames. USGS topo sheets, NOAA nautical charts, FEMA flood maps published from 2026 onwards will use NATRF2022 + NAPGD2022 by default.
3. State surveying conventions follow at their own pace. State Plane Coordinate Systems will be re-defined on NATRF2022; some states adopt quickly, others take years.
4. Software updates are needed. Code that hard-codes “NAD 83” or specific transformation parameters needs review. Code that uses EPSG codes through PROJ will be updated automatically when the new EPSG codes are registered.
5. Sub-metre work needs explicit attention. Mixing NAD 83 and NATRF2022 data without transforming will produce 1–2 m alignment errors — easily visible at survey scale.

How to prepare

For data producers:

• Begin tagging new datasets with the explicit reference frame (and its epoch) in metadata.
• Use EPSG codes rather than freeform datum names.
• Plan a migration path: when does your data go from NAD 83 to NATRF2022? What about legacy customers who still expect NAD 83?

For data consumers:

• Audit your tooling: do your GIS packages, surveying software, and database stored procedures correctly identify the source frame of incoming data?
• Validate transformations: the NGS NCAT service is authoritative for any NAD 83 ↔ NATRF2022 transformation.

For software developers:

• Update your library's default datums when new EPSG codes are registered.
• Test against both legacy and new frames during the transition window.
• Provide explicit datum metadata in every coordinate-bearing output, not just human-readable display.

Beyond NSRS modernization

The NSRS modernization is the US-specific case of a broader international trend: regional plate-fixed reference frames re-aligning to contemporary ITRF realizations every decade or so. Australia did this with GDA94 → GDA2020. Europe maintains ETRS89 with regular epoch updates. Canada will be updating CSRS to align with NATRF2022 as part of joint North American coordination.

The trend reflects the maturity of global GNSS observation: the contemporary Earth-centred reference frame (ITRF) is now precise enough that aligning regional frames to it produces sub-centimetre internal consistency, far better than the standalone regional frames of the 1980s.

Common misconceptions

“NSRS modernization is a single hard cutover.” It isn't. NAD 83 and the new frames will coexist for years. Federal mapping migrates first; state surveying conventions and private data take longer.

“NATRF2022 is the same as WGS 84.” Closely related but not identical. NATRF2022 is plate-fixed (attached to the North American plate); WGS 84 is Earth-mass-centred (follows plate motion). At the moment of the 2022 epoch they were aligned; they will drift apart at the plate-motion rate (~2 cm/year west- southwest in CONUS).

“NAVD 88 was good enough.” It was the best available in 1991 but has accumulated systematic tilts on the order of 1–2 m across CONUS. For hydrology, flood-zone mapping, and infrastructure crossing long distances, the tilt matters. NAPGD2022 with modern satellite gravity reduces the error by an order of magnitude.

“The new frames make all existing coordinates wrong.” They don't. NAD 83 coordinates remain valid in NAD 83. Whether to migrate to NATRF2022 is an engineering and data-management decision; the choice depends on the dataset's purpose and the accuracy budget.

“Only US-domestic work is affected.” Mostly true, but international data exchanges that include US federal data will need to handle the new frames. Software that depends on US datasets (Mapbox, Esri, Google Maps for US territory) will update their default reference frames over the rollout window.

“NATRF2022 makes NAD 83 obsolete overnight.” No. Decades of legacy data, infrastructure records, parcel boundaries, and published maps reference NAD 83. The frame remains valid for all that data; it just won't be the authored frame of new work. Bidirectional transformations between NAD 83 and NATRF2022 will be supported by NGS NCAT indefinitely.

“The new frames will need updating soon too.” Not on the same timeline. NATRF2022 is plate-fixed, so coordinates within the North American plate stay stable. The frame will be re-realized periodically (probably every 10–15 years) to fold in new GNSS observations, but each re-realization will be a small adjustment, not a wholesale frame change. Expect the NATRF2022-family frames to be the dominant US reference for at least the next 20–30 years.

“State Plane coordinates work the same in NATRF2022.” The same conceptual framework, but the parameters change. NGS is publishing new State Plane Coordinate System definitions that are projected on NATRF2022 instead of NAD 83. Coordinates in the new SPCS will differ from coordinates in the old SPCS by the same 1–2 m horizontal offset that separates the underlying datums. Every state surveying authority is responsible for adopting the new definitions; the timeline varies. Surveying records published before the adoption are NAD 83 SPCS; records after are NATRF2022 SPCS. Both reference frames will coexist for years.

With this article shipping, the Datums sub-hub closes: 1 pillar + 7 supports = 8 articles total. The full datum lifecycle — from the fundamental definition, through realization, transformation, vertical-system pairing, and now the active US modernization — is documented.