{
    "code": "83735",
    "coding_system": "CPT",
    "canonical_url": "https://localishealth.com/cpt/83735/2014/B",
    "release_specific_url": "https://localishealth.com/cpt/83735/2021/D",
    "description": "Measures magnesium in a blood sample. Magnesium is essential to muscle and nerve signalling and to a steady heart rhythm, and it has an important quirk: when it is low, potassium and calcium often refuse to come back up no matter how much of those are replaced, until the magnesium itself is corrected. Levels drop with poor nutrition, heavy alcohol use, ongoing losses from the gut, and several very common medications including diuretics and acid-reducing drugs.",
    "answer": {
        "question": "Did Medicare pay separately for CPT 83735 in Q4 2021?",
        "text": "Not at a published national rate. CPT 83735 carries status X (statutory exclusion) in the Q4 2021 release. The statutory definition of physician services does not include this item. Treat the blank amount as unpriced, not as $0."
    },
    "release": {
        "schedule": "pfs",
        "year": 2021,
        "quarter": "D",
        "label": "Q4 2021",
        "effective": "October 1 – December 31, 2021",
        "revision": 1
    },
    "status": {
        "code": "X",
        "non_facility_payable": false,
        "facility_payable": false
    },
    "national_rates_usd": {
        "office_non_facility": null,
        "facility": null,
        "sequestration_applied": false,
        "gpci": 1
    },
    "rvus": {
        "work": null,
        "practice_expense_non_facility": null,
        "practice_expense_facility": null,
        "malpractice": null
    },
    "formula": "(work_rvu × work_gpci + pe_rvu × pe_gpci + mp_rvu × mp_gpci) × conversion_factor",
    "conversion_factor": 34.8931,
    "source": {
        "label": "Physician relative value file (Q4 2021)",
        "cms_url": "https://www.cms.gov/files/zip/rvu21d.zip",
        "local_source_url": "https://localishealth.com/sources/physician-fee-schedule/2021/D",
        "file": "PPRRVU21_OCT.csv",
        "row": 14688,
        "sha256": "f1972bd23bdc51795ceba7d536bb413a0ba0b47fad8c2ed594e7ee7799877297"
    },
    "modified_at": "2026-08-04T03:10:59+00:00"
}