S70.221A Blister (nonthermal), right hip, initial encounter

ICD-10-CM S70.221A: Blister (nonthermal), right hip, initial encounter

ICD-10-CM code S70.221A identifies a nonthermal blister located on the right hip during an initial encounter. The terminology is active and classified under the semantic type of Injury or Poisoning. Medicare billing articles list this code alongside subsequent and sequela variants within operational coding contexts. 1 3 4 5

Plain-language overview

Code S70.221A is an active ICD-10-CM terminology concept representing a nonthermal blister on the right hip for an initial encounter, providing a standardized label for this specific injury. 1

What this code represents

The concept S70.221A is assigned the semantic type of Injury or Poisoning and has a parent concept designated as S70.221 for a nonthermal blister of the right hip. 1 5

The S70.221A code specifically denotes the initial encounter for a right hip nonthermal blister, distinct from the S70.221D subsequent encounter and S70.221S sequela codes. 3

Clinical context

Clinical literature indicates that blisters are a manifestation of second degree burn wounds, and the presence of blister skin can hinder the accurate evaluation of burn depth. 2

Documentation considerations

Terminology records establish the official label for S70.221A as Blister (nonthermal), right hip, initial encounter, and billing articles list this exact code alongside its subsequent and sequela variants. 1 3

Coverage and utilization context

The S70.221A code appears in Medicare billing and coding articles for debridement services and tetanus immunization administration, establishing its presence within these specific operational contexts. 3 4

A Medicare coverage article documents coding guidelines for tetanus toxoids administration that include the nonthermal right hip blister code within its listed instructions. 4

What the sources add

Terminology sources define the active status and hierarchical parent of S70.221A, while Medicare billing articles provide operational context by listing the code alongside its subsequent encounter and sequela variants. 1 3

Clinical consensus literature describes blister management considerations for burn wounds, while official terminology records strictly define the S70.221A code without detailing clinical treatment protocols. 1 2

Sources

1. ICD-10-CM S70.221A terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Consensus on the treatment of second-degree burn wounds (2024 edition) — pmc.ncbi.nlm.nih.gov; accessed 2026-07-27.
3. Article - Billing and Coding: Debridement Services (A56459) — cms.gov; accessed 2026-07-27.
4. Article - Billing and Coding: Tetanus Immunization (A52438) — cms.gov; accessed 2026-07-27.
5. EVS Explore — evsexplore.semantics.cancer.gov; accessed 2026-07-27.